Abstract Taking Chongqing typical red sandstone for study object,direct tensile creep test of the red sandstone is conducted by self-designed and developed uniaxial direct tension device. Based on test results,the uniaxial creep laws of axial creep,lateral creep and unloading creep are studied,and the characteristics of creep ruptures are also discussed. Finally,the modified nonlinear Nishihara model is used to describe the creep process of sandstone. Based on the Matlab programming of Levenberg-Marquardt(LM) optimization algorithm,the parameters of modified nonlinear Nishihara model are obtained. Comparison between creep model and experimental results shows that the modified nonlinear Nishihara model is applicability in the direct tensile creep of red sandstone. Conclusions of the study enrich the creep data of red sandstone in Chongqing and have positive significance for large-scale geotechnical engineering in this region.
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Received: 07 September 2010
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